Protective screen and visor produced therewith for a safety helmet, particularly a forestry worker&#39;s helmet

ABSTRACT

A protective screen to protect the face and, above all, the eyes of a person against flying particles and sharp objects has a mesh with a mesh structure which is formed from a plurality of adjacent rows of hexagonal openings, which rows are bounded by mesh webs common to the openings. The openings in the mesh are each osubstantially the same area. The mesh is enclosed by an edge with no mesh structure which has a width which is at least equal to the height of a row of openings in the mesh structure. The mesh webs of at least two rows of openings adjacent to the edge can be made thicker than the mesh webs for the other openings, wherein, however, all the openings in the mesh are nevertheless substantially identical in area. The mesh is produced by etching spring steel sheet. A visor for a safety helmet, especially a forestry worker&#39;s helmet is produced from the protective screen by injection moulding a supporting frame around its edge.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a protective screen for the face and above allthe eyes of a person, against flying particles and pointed objects, inparticular during forestry work, having a mesh with a mesh structurewhich is formed by a multiplicity of mutually adjacent rows ofnoncircular openings which are delimited by mesh webs which are commonto the openings.

2. Description of the Invention

A protective face screen of this type is known from document EP 1 182943 B1. The former is manufactured by etching metal, and comprises amesh which forms a large number of light-permeable openings, theopenings containing various surfaces. The protective screen has at leasttwo regions. The surface of each opening within each region is identicaland the surfaces of the openings in different regions differ. The meshis enclosed by a continuous rim, the width of which corresponds to aboutthe thickness of one of the mesh webs between adjacent openings of themesh. Such a rim cannot be expected to substantially contribute towardthe stability of the mesh. Once the protective screen isinsertion-molded with a support frame of plastic which encloses themesh, irregular transitions between the inner boundary of the supportframe and the mesh moreover arise, because the plastic spreads in anirregular manner into some openings of the mesh and not into otheropenings. Furthermore, the mesh of the known protective face screen inthe various regions has in each case different stability and strength,because the latter are determined on the one hand by the size of theopenings of the mesh, which differs in the various regions, and on theother hand by the thickness of the mesh webs, which likewise differs inthe various regions. The size of the surfaces which differs from regionto region also brings about that the mesh also has a degree of lighttransmission which differs from region to region.

Document FR-A-826 990 discloses a screen for protecting the human eyefrom excessive sunlight, which replaces the usual colored lenses insunglasses. The screen is composed of a circular plate which is adaptedso as to be insertable into the lens opening of a spectacle frame. Thescreen comprises a multiplicity of mutually adjacent rows of round, thatis to say circular, openings of the same diameter, or rows of circularopenings having two different diameters. There should be no problems inrespect of stability and quality of appearance in the case of the knownscreen, since the screen overall has only a diameter which in theinitial state of the screen is not much larger than the lens opening ofa spectacle frame in which said screen is gripped on its entirecircumference. Protective screens such as employed in a visor of aprotective helmet are many times larger and thus not comparable to aprotective screen of the size of a spectacle lens, at least not in termsof stability.

It is an object of the invention to improve stability in a mesh of thetype mentioned at the outset, and to improve the quality of appearanceof a support frame which is molded to the mesh. Moreover, a visor for aprotective helmet, particularly a forestry worker's helmet, is to beprovided.

SUMMARY OF THE INVENTION

Proceeding from a support frame of the type mentioned at the outset,this object is achieved according to the invention in that the openings,apart from part-openings which immediately adjoin a rim of the meshwhich is without a mesh structure, in each case have a substantiallyidentical surface area, wherein the rim encloses the mesh and along itscircumference has a width which is at least equal to a height of a rowof openings of the mesh structure. The large width of the rim of theprotective screen according to the invention substantially contributestoward increasing stability of the mesh. The same surface areas of theopenings of the mesh impart to the latter a degree of light transmissionwhich is substantially homogenous in the region of the entire mesh. Thewide rim moreover enables the protective screen according to theinvention to be provided with a support frame having a uniformly runninginner boundary.

A visor for a protective helmet, particularly a forestry worker'shelmet, which is manufactured from a protective screen according to theinvention, the rim of which is insertion-molded with a support frame ofplastic, has the desired increased stability and the targeted improvedappearance.

Advantageous design embodiments of the protective screen and of thevisor according to the invention form the subject matter of thedependent claims.

In one design embodiment of the protective screen according to theinvention the width of the rim is at least equal to the height of twovertically adjacent rows of openings of the mesh structure. Based on theminimum width of the rim which is used in this design embodiment, thisconfiguration imparts to the protective screen and to the visoraccording to the invention the targeted greater stability.

In one further design embodiment of the protective screen according tothe invention the rim is provided with clearance holes which aredistributed across its length and which predominantly are each smallerthan each of the mesh openings. These clearance holes are a fewclearance holes of a comparatively large diameter which as fitting holesfacilitate insertion of the protective screen into a processing machinein which the protective screen in its entirety is coated with aprotective layer, or in which the protective screen is insertion-moldedwith a support frame, and are substantially more clearance holes ofcomparatively small diameter through which the plastic can pass duringthe manufacture of the support frame in order to improve the connectionbetween the mesh and the support frame.

In a further design embodiment of the protective screen according to theinvention the minimum number of openings in the mesh per squarecentimeter is at least 15. The number of openings per square centimeterhere is selected according to the protection requirements. For example,if it is known that shavings of softwood arise during forestry work, acoarser mesh may be selected. However, a finer mesh should be selectedwhere shavings of hardwood arise. In the present context, coarse means,for example, 16 openings/cm², in contrast thereto fine means, forexample, 39 openings/cm².

In a further design embodiment of the protective screen according to theinvention the thickness of the mesh webs is selected so as to beinversely proportional to the number of openings per square centimeter.Thus, in the case of the selected coarse mesh having 16 openings/cm² thethickness of the mesh webs may be approx. 0.3 mm, in contrast thereto inthe case of the fine mesh having 39 openings/cm² approx. 0.2 mm. Theassociated height of one row of openings of the mesh structure in thetwo aforementioned examples may be approx. 3 mm or approx. 2 mm,respectively, wherein this value would then also be the minimum widthaccording to the invention of one row of openings of the mesh structure.

In a further design embodiment of the protective screen according to theinvention the mesh webs, that in a zone the width of which is at leastequal to the vertical height of one of the rows and that is adjacent tothe rim on its circumference, the mesh webs are configured to be thickerthan the mesh webs of the remaining openings. On account thereof, afurther increase in the already high and adequate stability per se ofthe protective screen according to the invention may be achieved.

In a further design embodiment of the protective screen according to theinvention the width of the zone is substantially equal to the height oftwo vertically adjacent rows of openings of the mesh structure. Incomparison to the overall mesh, the zone thus has a modest width which,however, on account of the mesh webs which are configured so as to bethicker within the zone, still substantially increases the strength andstability of the mesh. The degree of transmission within the zone issubstantially equal to the degree of transmission of the mesh outsidethe zone, since the surface areas of the openings which are surroundedby comparatively thick webs are substantially equal to those of theopenings which are surrounded by comparatively thin mesh webs.

In a further design embodiment of the protective screen according to theinvention the openings in the zone have the same vertical center spacingas the openings in the remaining mesh. The achieved additional rigidityof the mesh does not compromise the degree of light transmission, inparticular not in the so-called viewing opening, since the zone lies atthe rim of the mesh, and moreover since all openings of the mesh whichare outside and within the zone are disposed in the same grid pattern.

In a further design embodiment of the protective screen according to theinvention the mesh is manufactured from spring steel sheet. In thiscase, a thin metal sheet may be employed in order to achieve the desiredstability at the lowest weight of the protective screen and, inparticular, to ensure protection against high-velocity particles.

In a further design embodiment according to the invention the mesh ismanufactured by etching. Etching is the preferred manufacturing methodwhen metal is employed for the mesh of the protective screen. Protectiveface screens may indeed also be manufactured from a woven metal wire orplastic mesh, but such meshes have various disadvantages for the carrierwhich etched metal meshes do not have. Such disadvantages include, forexample, that the wires occupy a large part of the entire surface of themesh and result in lower stability and mechanical strength than anetched metal mesh. Moreover, such woven wire or plastic meshes may bepierced by pointed objects, such as pointed branches or twigs, becausewires or plastic threads are displaceable in relation to one another.

In one design embodiment of the visor according to the invention aninner boundary of the support frame which faces the mesh has a spacingfrom an inner circumference of the rim which adjoins the mesh. Onaccount thereof, a clean appearance of the inner boundary of the supportframe is ensured in a simple manner.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the invention are described in more detail inthe following with reference to the drawings, in which:

FIG. 1 shows a plan view of a first exemplary embodiment of a protectivescreen according to the invention, having a mesh of spring steel sheet;

FIG. 1 a shows a detail of the protective screen according to FIG. 1 ina larger scale;

FIG. 2 shows a second exemplary embodiment of the protective screenaccording to the invention, having a mesh of spring steel sheet whichhas a finer mesh structure than the mesh of the first exemplaryembodiment;

FIG. 2 a shows a detail of the protective screen according to FIG. 2 ina larger scale;

FIG. 3 shows a third exemplary embodiment of the protective screenaccording to the invention, which corresponds to the first exemplaryembodiment but has a different mesh structure in the peripheral region;

FIG. 3 a shows as a detail the peripheral region of the protectivescreen according to FIG. 3 in a larger scale;

FIG. 4 shows a fourth exemplary embodiment of the protective screenaccording to the invention, which corresponds to the second exemplaryembodiment but in a zone which is adjacent to the rim has a differentmesh structure; and

FIG. 4 a shows as a detail the zone and an adjacent region of theprotective screen according to FIG. 4 in a larger scale.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a plan view of a first exemplary embodiment of a protectivescreen according to the invention, which in its entirety is referred toas 10, having a mesh 12 of a thin spring steel sheet.

FIG. 1 a shows a detail of the protective screen 10 according to FIG. 1in a larger scale. The mesh 12 has a mesh structure which is formed froma multiplicity of mutually adjacent rows of noncircular openings 14.According to the illustration in FIG. 1 a, the openings are in each casehexagonal and delimited by common mesh webs 16 which have a thickness D.Apart from part-openings 13 which immediately adjoin an encircling rim18, which is without a mesh structure, but which are negligible in theoverall scheme, the openings 14 of the mesh 12 have in each caseidentical surface areas. Furthermore, on account of this construction,in each case two adjacent rows of openings 14 of the mesh have one andthe same vertical center spacing M.

The mesh 12 is enclosed by the rim 18 which has a width B which is atleast equal to a height H of one row of openings 14 of the meshstructure. Preferably, the width of the rim 10 is at least equal to theheight of two vertically adjacent rows of openings 14 of the meshstructure.

The rim 18 is provided with clearance holes 15, 17 which are distributedacross its length and which predominantly are each much smaller thaneach of the openings 14 of the mesh 12. In the case of the firstexemplary embodiment of the protective screen 10 which is illustrated inFIGS. 1 and 1 a, these clearance holes are clearance holes 15 of acomparatively large diameter and predominantly clearance holes 17 of acomparatively small diameter. Each clearance hole 15 substantially has asurface area which is identical to one of the openings 14 of the meshstructure. The clearance holes 15 of a comparatively large diameter arefitting holes which facilitate the insertion of the protective screen 10into a processing machine in which the protective screen in its entiretyis coated with a protective coating and/or in which the protectivescreen is insertion-molded with a support frame (not illustrated). Theclearance holes 17 of a comparatively small diameter, of which there aresubstantially more than of the clearance holes 15 of a comparativelylarge diameter, enable the plastic to pass through during molding of asupport frame 52 which is indicated in FIG. 4, in order to improve theconnection between the mesh 12 and the support frame 52.

FIG. 2 shows a second exemplary embodiment of a protective screenaccording to the invention, which in its entirety is referred to as 20,having a mesh 22 of spring steel sheet which has openings 24 which aresmaller than the openings 14, and has a finer mesh structure than themesh 12 of the first exemplary embodiment. The minimum number ofopenings 14, 24 per square centimeter in the mesh 12 or 22,respectively, is at least 15, according to DIN EN 1731. The actuallyused number of openings in the mesh is selected according to theprotective requirements, that is to say according to whether, forexample, protection against flying particles which are softwood shavingsor hardwood shavings is to be ensured. The mesh 22 has mesh webs 26which have a thickness D which is inversely proportional to the numberof openings per square centimeter. In the first exemplary embodiment ofthe protective screen according to the invention the mesh 12 is acomparatively coarse mesh having sixteen openings 14 per squarecentimeter. In the second exemplary embodiment of the protective screen20 according to the invention the mesh 22 is a comparatively fine meshhaving thirty-nine openings 24 per square centimeter. The details whichare shown in FIGS. 1 a and 2 make it apparent that the thickness D ofthe mesh webs 16 in the comparatively coarse mesh 12 is greater than thethickness D in the comparatively fine mesh 22. The details in FIGS. 1 aand 2 a are illustrated on the same scale of enlargement, such that itis immediately obvious that the comparatively coarse mesh 22 hassubstantially fewer rows and openings 14 than the comparatively finemesh 22 has rows of openings 24. The openings 24 of the mesh 22 all haveidentical surface areas. The same applies to the openings 14 of the mesh12, wherein however the mesh 22, having an identical surface area tothat of the mesh 12, has substantially more openings 24 than the mesh 12has openings 14.

FIG. 3 shows a third exemplary embodiment of the protective screenaccording to the invention, which in its entirety is referred to as 30and which corresponds to the protective screen 10 according to the firstexemplary embodiment, but has a different mesh structure in theperipheral region. As a detail, FIG. 3 a shows the peripheral region ofthe protective screen 30 according to FIG. 3 on a larger scale. Sameparts as in FIGS. 1 and 2 are provided with the same reference signs inFIGS. 3 and 4 and do not require renewed description.

In the exemplary embodiments according to FIGS. 3 and 4, mesh webs 36 aand 46 a, respectively, of openings 34 a and 44 a, respectively, whichlie in a zone 70 (shown in the figure as having a dashed delimitation)adjacent to the rim 38 and 48, respectively, have a larger thickness Dthan mesh webs 36 b and 46 b, respectively, of the remaining openings 34and 44, respectively. Here, openings 34 and 34 a or 44 and 44 a,respectively, in adjacent rows outside or within the zone 70,respectively, have the same vertical center spacing M as the openings inthe remaining adjacent rows of the mesh 32 and 42, respectively.

The zone 70 has a width BZ which is at least equal to the verticalheight H of one of the rows. In the exemplary embodiments according toFIGS. 3 and 4 the width BZ of the zone 70 substantially is equal to theheight of two vertically adjacent rows of openings 34 or 44,respectively, of the mesh structure. For improved clarity of theopenings 44 a which lie within the zone 70, their areas are marked withdots in FIG. 4 a. The comparatively thick webs of the openings 44 a areachieved by way of a somewhat modified hexagonal shape within theopenings 44 a in relation to the hexagonal shape within the openings 44.In the corners of the hexagon of the openings 44 a, said corners areconfigured so as to be rounded, in contrast to the corners of thehexagon of the openings 44, which have no curvature radius. In this way,thicker webs 46 a of the openings 44 a than the webs 46 b of theopenings 44 are achieved while maintaining the grid pattern,specifically while maintaining a substantially identical surface area ofthe openings 44 a and 44.

The protective screens 10, 20, and 30, like the protective screen 40,may be provided with a zone 70 in which the mesh webs are configured soas to be thicker than in the remaining part of the mesh 12, 22, and 32,respectively.

In all exemplary embodiments which are described above and illustratedin the drawings the mesh 12, 22, 32, and 42, respectively, ismanufactured from spring steel sheet, specifically by etching. Accordingto a photolithographic process or similar, the mesh structure is appliedonto the metal sheet, using a protective lacquer. The mesh is etchedfrom all points which are not covered by the lacquer, in order tomanufacture in this manner the desired mesh structure having the widerim 18, 28, 38, and 48, respectively, which encloses the mesh structure.

The protective screen 10, 20, 30, and 40, respectively, isinsertion-molded with a support frame of plastic, and is thus employableas a visor for a protective helmet, particularly a forestry worker'shelmet. Here, according to the illustration indicated in FIG. 4, aninner boundary 50 of an indicated support frame 52, which faces the mesh42, has a spacing A from an inner circumference 54 of the rim 48, whichadjoins the mesh 42. On account thereof, the support frame 52 has nocontact with the actual mesh 42 and, after manufacturing, has a uniforminner delimitation.

LIST OF REFERENCE SIGNS

-   10 Protective screen-   12 Mesh-   13 Part-opening-   14 Opening-   15 Clearance hole-   16 Mesh web-   17 Clearance hole-   18 Rim-   20 Protective screen-   22 Mesh-   23 Part-opening-   24 Opening-   26 Mesh web-   28 Rim-   30 Protective screen-   32 Mesh-   33 Part-opening-   34 a Opening-   36 a Mesh web-   36 b Mesh web-   38 Rim-   40 Protective screen-   42 Mesh-   43 Part-opening-   44 Opening-   44 a Opening-   46 a Mesh web-   46 b Mesh web-   48 Rim-   50 Boundary-   52 Support frame-   54 Inner circumference-   A Spacing-   B Width-   D Web thickness-   H Height-   M Center spacing-   BZ Zone width

1. A protective screen for protecting a face of a user from flyingparticles and pointed objects, the protective screen comprising: a meshhaving a mesh structure, the mesh structure comprising a plurality ofmutually adjacent rows, each of the rows having a plurality of firstopenings and a plurality of mesh webs, the first openings comprising anon-circular shape, each of the first openings having a substantiallyidentical surface area, the plurality of mesh webs respectively definingthe plurality of first openings; and a rim enclosing the mesh along acircumference of the mesh, a plurality of second openings immediatelyadjoining the rim; wherein the rim has a width at least equal to aheight of the first openings.
 2. The protective screen as claimed inclaim 1, wherein the width of the rim along a circumference of the rimis at least equal to the height of two vertically adjacent rows of firstopenings.
 3. The protective screen as claimed in claim 1, wherein therim is provided with a plurality of clearance holes, the plurality ofclearance holes being distributed across a length of the rim, at least amajority of the clearance holes each being smaller than the firstopenings.
 4. The protective screen as claimed in claim 1, wherein aminimum number of first openings in the mesh per square centimeter is atleast
 15. 5. The protective screen as claimed in claim 1, furthercomprising an enhanced zone, the zone comprising a width at least equalto the vertical height of one of the plurality of rows and beingadjacent to the rim on a circumference of the rim, wherein a respectiveplurality of the mesh webs in the zone are thicker than a respectiveplurality of mesh webs outside the zone.
 6. The protective screen asclaimed in claim 5, wherein a width of the zone is substantially equalto a height of two vertically adjacent rows of first openings of themesh structure.
 7. The protective screen as claimed in claim 5, whereinthe first openings in the zone have a same vertical center spacing asthe first openings outside the zone.
 8. The protective screen of claim1, wherein the mesh comprises a spring steel sheet.
 9. The protectivescreen as claimed in claim 8, wherein the mesh is manufactured byetching.
 10. A visor for a protective helmet, the helmet comprising: aprotective screen for protecting a face of a user from flying particlesand flying objects, the protective screen comprising a mesh having amesh structure, the mesh structure comprising a plurality of mutuallyadjacent rows, each of the rows having a plurality of first openings anda plurality of mesh webs, the first openings comprising a non-circularshape, each of the first openings having a substantially identicalsurface area, the plurality of mesh webs respectively defining theplurality of first openings; and a rim enclosing the mesh along acircumference of the mesh, a plurality of second openings immediatelyadjoining the rim; wherein the rim has a width at least equal to aheight of the first openings; wherein the rim is insertion-molded with asupport frame of plastic.
 11. The protective screen as claimed in claim2, wherein the rim is provided with a plurality of clearance holes, theplurality of clearance holes being distributed across a length of therim, at least a majority of the clearance holes each being smaller thanthe first openings.
 12. The protective screen as claimed in claim 2,further comprising an enhanced zone, the zone comprising a width atleast equal to the vertical height of one of the plurality of rows andbeing adjacent to the rim on a circumference of the rim, wherein arespective plurality of the mesh webs in the zone are thicker than arespective plurality of mesh webs outside the zone.
 13. The protectivescreen as claimed in claim 12, wherein a width of the zone issubstantially equal to a height of two vertically adjacent rows of firstopenings of the mesh structure.
 14. The protective screen as claimed inclaim 12, wherein the first openings in the zone have a same verticalcenter spacing as the first openings outside the zone.
 15. Theprotective screen as claimed in claim 6, wherein the first openings inthe zone have a same vertical center spacing as the first openingsoutside the zone.
 16. The protective screen of claim 2, wherein the meshcomprises a spring steel sheet.
 17. The protective screen of claim 5,wherein the mesh comprises a spring steel sheet.
 18. A method ofmanufacturing a visor for a protective helmet, the helmet comprising aprotective screen for protecting a face of a user from flying particlesand flying objects, the protective screen comprising a mesh having amesh structure, the mesh structure comprising a plurality of mutuallyadjacent rows, each of the rows having a plurality of first openings anda plurality of mesh webs, the first openings comprising a non-circularshape, each of the first openings having a substantially identicalsurface area, the plurality of mesh webs respectively defining theplurality of first openings; and a rim enclosing the mesh along acircumference of the mesh, a plurality of second openings immediatelyadjoining the rim; wherein the rim has a width at least equal to aheight of the first openings; the method comprising the step of:insertion-molding the rim with a support frame of plastic.
 19. Themethod of claim 18, further comprising the step of: manufacturing themesh from spring steel sheet.
 20. The method of claim 19, wherein thestep of manufacturing the mesh from spring steel sheet is performed byetching.